title: Standardized voluntary force measurement in a lower extremity rehabilitation robot.
abstract: BACKGROUND
  Isometric force measurements in the lower extremity are widely used in rehabilitation of subjects with neurological movement disorders (NMD) because walking ability has been shown to be related to muscle strength. Therefore muscle strength measurements can be used to monitor and control the effects of training programs. A new method to assess isometric muscle force was implemented in the driven gait orthosis (DGO) Lokomat. To evaluate the capabilities of this new measurement method, inter- and intra-rater reliability were assessed.
  
  
  METHODS
  Reliability was assessed in subjects with and without NMD. Subjects were tested twice on the same day by two different therapists to test inter-rater reliability and on two separate days by the same therapist to test intra-rater reliability.
  
  
  RESULTS
  Results showed fair to good reliability for the new measurement method to assess isometric muscle force of lower extremities. In subjects without NMD, intraclass correlation coefficients (ICC) for inter-rater reliability ranged from 0.72 to 0.97 and intra-rater reliability from 0.71 to 0.90. In subjects with NMD, ICC ranged from 0.66 to 0.97 for inter-rater and from 0.50 to 0.96 for intra-rater reliability.
  
  
  CONCLUSIONS
  Inter- and intra- rater reliability of an assessment method for measuring maximal voluntary isometric muscle force of lower extremities was demonstrated. We suggest that this method is a valuable tool for documentation and controlling of the rehabilitation process in patients using a DGO.
authors.affiliation: Spinal Cord Injury Center, Balgrist University Hospital, Zurich, Switzerland. mbolliger@paralab.balgrist.ch
authors.forename: Marc
authors.initials: M
authors.lastname: Bolliger
authors.forename: Raphael
authors.initials: R
authors.lastname: Banz
authors.forename: Volker
authors.initials: V
authors.lastname: Dietz
authors.forename: Lars
authors.initials: L
authors.lastname: Lünenburger
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000502:physiology; D009468:Neuromuscular Diseases / Q000534:rehabilitation*; D015203:Reproducibility of Results; D012371:Robotics